Ca(v)3.2 calcium channels control an autocrine mechanism that promotes neuroblastoma cell differentiation.

Calcium influx via low-voltage activated alpha(1H) (Ca(v)3.2) T-currents participates in the morphological and electrical differentiation of neuroblastoma NG108-15 cells. We investigated whether an autocrine mechanism could contribute to this differentiation process. The presence of factors secreted by NG108-15 cells was identified through the use of conditioned media (CM) obtained from differentiated cells. These CM significantly increased neuritogenesis with no change in the HVA calcium channel expression. CM-induced neuritogenesis persists during alpha(1H) current block, whereas CM obtained from cells transfected with an alpha(1H) antisense did not induce neuritogenesis. These data indicate that morphological differentiation of NG108-15 cells depends on an autocrine mechanism, which is controlled by alpha(1H) currents. Such a mechanism is likely to play a role in the various differentiation processes that imply alpha(1H) T-type Ca(2+) channels.